At the dealer picking up some accessories and mentioned low coolant to service manager. He said not to worry and it happens and gave me a one liter bottle (like an oil bottle) of BMW antifreeze. Easier than carrying a gallon. He said mixture is 50:50 with water and when I mentioned picking up some distilled water at the market, he said it's not necessary and 'nobody uses distilled water anymore'. Really? Well, I'll pick some up anyway .
2013 x35i (Space Gray, MSport, CW/CWII, DHP, Premium, Premium Sound, Technology, BMW-Apps)
Retired:'09 C300 4Matic, '09 GTI, '06 750i, '05 C55, '04 R32, '03 M5, '02 GTI, 01 M5, '00 M-Coupe, '00 540i/6, '99 M3 Coupe, '98 M3 Coupe, '96 328i, ..., '86 4000CS Quattro, ... too many to list